One of the great ironies of my life: I asked my gay stepbrother if he thought the gov't should allow polygamous marriage. His response? "That's disgusting!" So, what's the standard? The fickle rule of man?
So, I think we should decouple secular law from religious law and give churches jurisdiction over the marriages of their followers -- and perhaps other areas. I think that would enhance the government's role as preserver as oppose to destroyer. And it would accomodate diverse viewpoints including those of polygamists. The key is: You voluntarily subject yourself to your church's jurisdiction until you renounce your membership.